purpose
/ˈpɜːpəs/
An objective to be reached; a target; an aim; a goal.
A result that is desired; an intention.
The act of intending to do something; resolution; determination.
The subject of discourse; the point at issue.
The reason for which something is done, or the reason it is done in a particular way.
The purpose of turning off the lights overnight is to save energy.
Instance; example.